1. Field of the Invention
The present invention relates to a medical imaging system, a medical image processing apparatus, and a computer-readable medium.
2. Description of the Related Art
In recent years, digital still images are generated for medical purposes by capturing images of diagnostic regions as subjects, and image diagnosis is done based on such medical images generated.
When there are motions in a subject while capturing a medical image, a subject blur happens in the medical image and motion artifacts are caused as slight burring of the human anatomy is imaged. Since an image that includes motion artifacts is not appropriate for diagnostic use, such medical image having motion artifacts requires a retake.
Therefore, for example, Patent Literature 1 (the publication of Japanese Patent No. 4539186) disclosed a technology in which it is judged whether there are motions in a subject while capturing a still image for medical purposes, and a medical image including motion artifacts is thus prevented from being used for diagnosis and efficiency of imaging operations is improved. In this Patent Literature 1, high spatial frequency components in the medical image are extracted, and existence of motions is judged based on the high spatial frequency components extracted.
Incidentally, in a case of a medical image of the front chest in which the lung field is captured as a subject, motion artifacts may happen due to breathing motions during radiation exposure for radiography. In such a case, the rib bones of the subject are imaged while remaining still, and motion artifacts happen in the blood vessels in the lung field of the subject.
In order to judge existence of motions in this kind of medical image, it is required to extract high spatial frequency components of the blood vessel regions in the lung field where motion artifacts happen. At this time, if edges of the rib bones are included in the regions where the high spatial frequency components are extracted, a problem arises that existence of motions cannot be judged correctly based on the extracted high spatial frequency components because the edges contain a number of high spatial frequency components.